Hydraulic systems are often used to control the operation of hydraulic actuators of machines. These hydraulic systems typically include valves, arranged within hydraulic circuits, fluidly connected between the actuators and pumps. These valves may each be configured to control a flow rate and direction of pressurized fluid to or from respective chambers within the actuators.
In some instances, multiple actuators may be connected to a common pump. During actuation of multiple actuators one actuator may require a significantly higher pressure from the pump than other actuators. Actuation of one such actuator may also create undesirable pressure or flow conditions in other parts of the system. The pressure and flow of the fluid provided to each actuator can be controlled, in part, by valves between the pump and the actuator. It is generally desirable to control the valves in a way that improves the efficiency of the system.
One method of reducing pressure fluctuations in hydraulic systems is described in U.S. Pat. No. 5,878,647 (“the '647 patent”) issued to Wilke et al. While the hydraulic circuit described in the '647 patent may reduce pressure fluctuations, it may also result in unnecessarily high system pressure.